Group I base oils, especially in Europe, have evolved to meet automotive standards for viscosity index and volatility by more severe solvent extraction and by narrow-cut distillation. While this meets volatility targets and slightly improves viscometrics for blending engine oils, it is an inefficient approach to the problem. Examples of the current Group I base oils that meet automotive standards are Esso150SN and Esso145SN in Europe and ExxonMobil 150SN in North America.
Light Fischer-Tropsch derived base oils and blends of these light base oils are known, but none of the prior art base oils or blends have the desired low wt % Noack volatility of this invention.
What is desired are light base oil fractions having improved wt % Noack volatility that are useful in lubricant base oil blends and finished lubricants. What is also desired is a base oil blend, utilizing light base oil fractions having a wt % Noack volatility less than a Noack Volatility Factor, that is equivalent or better in terms of viscometrics and volatility to current Group I base oils that meet automotive standards. High quality light base oil fractions, made from waxy feeds, having a Noack volatility less than a Noack Volatility Factor, can now be made available in large quantities and at low cost, making them desired components to include in automotive engine oils and other finished lubricant applications.